Vulcanization of unsaturated ethylene-alpha-olefin rubbers

ABSTRACT

VULCANIZED UNSATURATED ETHYLENE-PROPYLENE RUBBERS HAVING IMPROVED RESISTANCES TO TEAR AND CRACK GROWTH ARE PRODUCED BY THE SAME OF A VULCANIZATION SYSTEM COMPRISING THIURAM ACCELERATORS AND/OR DITHIOCARBAMATE ACCELERATORS, TOGETHER WITH AN AMINE OF THE FORMULA:   R1-N(-R2)-R3   WHEREIN R1 IS AN ALKYL, HYDROXYALKYL, ALKYLOXYALKYL, OR ALKENYLOXYALKYL RESIDUE; R2 IS H, OR A CYCLOALKYL RESIDUE; AND R3 IS H, OR AN ALKYL, HYDROXYALKYL, ALKYLOXAYALKYL, OR ALKENYLOXYALKYL RESIDUE. THIS SYSTEM ALSO RESULTS IN A SUBSTANTIALLY INCREASED VULCANIZATION VELOCITY, AS COMPARED TO PRIOR ART SYSTEMS.

United States Patent 3,654,243 VULCANIZATION 0F UNSATURATED ETHYLENE-a-OLEFIN RUBBERS Harald Bliimel, Marl, Germany, assignor to Chemische Werke Huls A.G., Marl, Germany No Drawing. Filed Oct. 13, 1965, Ser. No. 495,695 Claims priority, applicatior; 1(liermany, Oct. 16, 1964,

rm. or. miss 27/06 US. Cl. 26079.5 B 21 Claims ABSTRACT OF THE DISCLOSURE Vulcanized unsaturated ethylene-propylene rubbers having improved resistances to tear and crack growth are produced by the use of a vulcanization system comprising thiuram accelerators and/ or dithiocarbamate accelerators, together with an amine of the formula:

This invention relates broadly to a vulcanizable composition and more particularly to a mixture of vulcanization accelerators and promoters for unsaturated ot-olefin rubber.

It is known that vulcanized products composed of unsaturated ethylene-a-olefin rubbers possess good mechanical properties because of their relatively low degree of unsaturation, and are also highly resistant to aging caused by light, oxygen, and heat. However, there are also disadvantages attendant the use of products having a low degree of unsaturation, such as the slow rate at which they vulcanize in comparison to the vulcanization rate of the highly unsaturated rubber types, such as, for example, natural rubber, butadiene-acrylonitrile rubber, polybutadiene rubber, butadiene-styrene rubber, and polychloroprene rubber.

Therefore, it was heretofore necessary to |vulcanize rubber mixtures containing unsaturated ethylene-ot-olefin rubber with so-called ultra-accelerators which are principally thiuram and dithiocarbamate compounds and mixtures thereof. (These ultra-accelerators are employed with highly unsaturated rubbers in only special cases since they introduce unpredictable parameters into the vulcanization process, such as scorching.)

The aforementioned rubber mixtures optionally contained fillers, plasticizers, stabilizers, vulcanization promoters, accelerators, and other substances conventionally incorporated into rubber mixtures. With respect to certain amine additives, in particular, such as hexamethylene tetramine, diphenyl guanidine, and diorthotolyl guanidine, though, they have been widely used in accelerators or accelerator-activators in admixtures with the highly unsaturated rubbers. When these amines, commonly used for highly unsaturated polymers, are used solely in unsaturated ethylene-a-olefin rubber, the rate of vulcanization and the properties of the vulcanized product are very unsatisfactory. Even when they are used together with other accelerators in unsaturated ethylene-m-olefin rub ber, the vulcanization process will be retarded.

3,654,243 Patented Apr. 4, 1972 With the vulcanization systems described hereinbefore it was not possible to attain economically attractive rates of vulcanizing ethylene-ot-olefin rubber mixtures, i.e., vulcanization periods during which of the maximally achievable modulus value are obtained, particularly when using lower and moderate vulcanization temperatures. The absolute modulus values of the rubber obtainable under these conditions are also too high for many applications, this being especially true in case of ethylenea-olefin rubbers containing dicyclopentadiene as the unsaturated component. Furthermore, the tear resistance and concomitant dynamic resistance to crack growth upon flexure are often lower than those of other synthetic rubbers.

It is therefore a principal object of the invention to provide an improved composition which will accelerate the vulcanization of unsaturated ethylene-a-olefin rubber.

It is another object of this invention to provide a vulcanization process which will aid in the production of an ethylene-a-olefin rubber having improved properties.

It is still another object of the invention to provide ethylene-a-olefin rubbers having improved properties.

These and other objects, aspects and advantages of the invention will be apparent from the following description and appended claims.

It was discovered that unsaturated ethylene-a-olefin rubber can be substantially more rapidly vulcanized, with a simultaneous improvement in the tear resistance and the resistance to crack growth upon flexure of the vulcanized products, when a vulcanization system of the present invention is utilized. It was surprisingly discovered that the method of vulcanizing these rubbers and the resulting rubber is improved by employing as vulcanizing ingredients based on the weight of the terpolymer 0.25 to 5.0% by weight, preferably 1.0 to 2.0% by weight of a thiuram or dithiocarbamate ultra-accelerator; 0.25 to 3.5% by weight, preferably 0.75 to 1.5% by weight of sulfur; and 0.15 to 5.0% by Weight, preferably 1.0 to 2.0% by weight, of one or several amines of the general formula wherein R represents alkyl preferably having 1 to 20, more preferably 1 to 16 carbon atoms; hydroxyalkyl preferably having 1 to 5, more preferably 1 to 2 hydroxy radicals attached to an alkyl radical preferably having 1 to 2-0, more preferably 1 to 16 carbon atoms, the ratio of hydroxy radicals to carbon atoms being preferably 0.1 to 1 more preferably 0.5 to 1, and with the positioning of the hydroxy radicals in the alkyl radical being preferably to alkyloxyalkyl wherein the alkyl preferably contains 1 to 20, more preferably 1 to 16 carbon atoms;

alkenyloxyalkyl having preferably 1 to 20, more preferably 1 to 16 carbon atoms, and preferably 1 to 3, more preferably one double bond, the double bond being preferably positioned with respect to the oxy atom at w or amino alkyl having preferably 1 to 20, more preferably 1 to 1-6 carbon atoms, and preferably 1 to 5, more preferably 1 to 2 amino radicals positioned preferably to, resp. oz, 5, 'y to.

R is H, or a cycloalkyl residue having preferably 5 to 20, more preferably 5 to 10 carbon atoms and preferably 1 to 2 rings;

R is H or R as previously defined.

Amines embraced within the above structural formula and preferred for use in this invention are, for example,

(a) cyclohexyl amine, (b) aminopropyl alcohol, (c) laminopropanol-Z, (d) n-butyl amine, (e) stearyl amine, (f) lauryl amine, (g) di-3aminopropyl ether, (h) 3-lauryloxy propyl amine, (i) 3-allyloxy-2-oxypropyl amine-1, (j) polyethylene polyamine, (k) N,N-dietl1ylarninopropylamine, (l) N,-N-diethylethylene diamine, (m) [di-(2- oxypropyl)j-ethanolamine, (n) N-(n-butyD-diethanolamine, (o) cyclohexylethylamine, (p) 3-butoxypropylamine, (q) N,N-dibutylaminopropylamine, (r) N,N-dimethylaminopropylamine, (s) (2,2'-dioxy 3,3 diallyloxy) -dipropylamine.

It is to be understood that ethylene-a-olefin rubber means copolymers formed using a Ziegler-type catalyst system or an equivalent thereof with to 90, preferably 20 to 60 mol percent ethylene, and

10 to 80, preferably 40 to 70 mol percent another ot-monoolefin having 3 to 8, and preferably 3 to 4 carbon atoms and in particular propylene, or a-butylene.

0.1 to 20, preferably to 10 weight percent, based on the total terpolymer of at least one additional, polymerizable polyunsaturated compound, being preferably hydrocarbon, advantageously of 4 to 30, more preferably 4 to 20 carbon atoms and 2 to 5, preferably 2 to 3 double bonds per monomer, such as, for example, dicyclopentadiene, hexadiene-l,4, decatriene-1,4,9, cyclooctadime-1,5, norbornene, as well as its alkenyl derivatives or suitable addition products of polyunsaturated compounds as S-methylene norbornene, butenyl norbornene.

The thiuram or dithiocarbamate accelerator can be, for example, (a) tetramethyl thiuram disulfide, (b) tetramethyl thiuram monosulfide, (c) zinc-N-diethyl dithiocarbamate, (d) zinc-N-dibutyldithiocarbamate, (e) N-cyclohexyl ethylammonium-N-cyclohexylethyldithiocarbamate, (f) zinc-N-dimethyl dithiocarbamate, (g) zinc-N- ethylphenyldithiocarbamate, (h) zinc-N-pentamethylendithiocarbamate, (i) dimethyldiphenylthiuramdisulfide, or (3') dipentamethylene thiuram tetrasulfide.

The amines to be utilized herein can be added to the rubber hydrocarbon, alone or together with another component of the mixture. The amines can be added, for example, during the process of forming the polymer; while the polymer is being worked up; in a separate process step before the mixture is produced; or only after other components of the composition have been admixed. The subsequent vulcanization is conducted in a conventional manner in a vulcanization equipment normally used, e.g. mold or press. However, it is also possible to utilize special vulcanization methods, such as hot-air vulcanization, continuous vulcanization (CV vulcanization), or vulcanization by the injection molding process, and other related methods. The vulcanization is preferably carried out at 140 to 220 C., more preferably 150 to 180 C.

Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The following preferred specific embodiments are, therefore, to be construed as merely illustrative, and not lirnitative of the remainder of the specification and claims in any way whatsoever.

EXAMPLE 1 In Table I, a conventional vulcanizable composition A for ethylene-u-olefin rubber is compared with a vulcanizable composition B which represents a preferred embodiment of the present invention. In Table 2 composition A is utilized in runs I, III, and V, and composition B in runs II, IV, and VI. For each of the runs tabulated in Table 2, an ethylene-propylene rubber having dicyclopentadiene as the unsaturated component, a content of propylene of about 45 molar percent, and a Mooney plasticity of ML4=ca. 45 is utilized. In runs I and II, a rubber having a lower degree of unsaturation is employed; in runs III and IV a rubber of medium unsaturation is used, and runs V and VI use a rubber of higher unsaturation.

The runs utilizing composition A characterizing the state of the art, are shown in Table 2. These results also show that there is no substantial increase in the vulcanization rate when the dicyclopentadiene content of the ethylene-propylene rubber is increased from about 5% by weight, as in run III, to about 9% by weight, as in run V. This can be easily recognized graphically if desired, by plotting the modulus percentages at the bottom of Table 2 against the dicyclopentadiene content tabulated in the second column.

The modulus percent is a measure of the vulcanization velocity, since the degree of vulcanization at the end of a predetermined uniform vulcanization period is represented as a percentage of the vulcanization maximally obtainable for the mixture in question. The compositions used in runs I, III and V exhibit different absolute values of moduli (300% elongation) owing to differing degrees of vulcanization corresponding to the specific degree of unsaturation of the rubber used therein.

Runs II, IV and VI were made using composition B with differing quantities of dicyclopentadiene. Although composition B vulcanizes markedly faster than composition A, the formation of plateaus commences earlier and the rate of vulcanization is greatest in the rubber having the least degree of unsaturation (i.e. least amount of dicyclopentadiene.). Thus a comparison of the modulus percent for runs I and II clearly illustrates the effect of the vulcanization promoters of this invention on rubbery compositions having a low degree of unsaturation. In addition to the effect accompanying the use of rubbers having a low degree of unsaturation, it is also apparent in runs II, IV, and VI that there is also observed in these compositions containing the amines of this invention a general decrease in the moduli and an increase in the elongation. There is also observed a marked improvement in the tear resistance and an increase in the resistance to crack growth upon flexing which, in some instances, can amount to more than 50%.

It is thus of particular interest that advantageous properties can be obtained from compositions vulcanized in accordance with this invention with a lower degree of vulcanization on the one hand, and an increased rate of vulcanization on the other. Furthermore, by the use of the amine additive of the invention, there are no substantial differences in the vulcanization rate of rubbers having a lower degree of unsaturation and those having a higher degree of unsaturation. The practical significance of the foregoing discovery resides in that, for one, the rubbers having a lower degree of unsaturation, can be produced more easily and economically, and owing to improved properties, better aging characteristics, are useful in an enlarged field of application. Another benefit of the present process is that polyunsaturated components which were formerly undesirable because of their slow vulcanization rate can be used in unsaturated ethylene-propylene rubbers to produce rubbery materials having superior properties. Thus, the present vulcanization process now makes available a class of rubbers having various tercomponents which heretofore were of only minor practical importance because of their low vulcanization rate.

By the selection of the amount of amine and the amount of the other vulcanizing agents within the disclosed ranges, the vulcanization velocity can be adjusted to ranges suitable for specific purposes. That is, the properties of the vulcanized product, such as modulus, tear resistance, elongation, can be tailored for specific uses as can be seen from Example 2.

EXAMPLE 2 In Table 3 there are shown five different compositions of which C is an example of the conventionally utilized vulcanization compositions, while D, E. F and G are variants of the present compositions. The results of vulcanization runs made with these various compositions are shown tabulated in Table 4. In addition to the markedly increased vulcanization rate and improved properties of the resulting rubber, it is now possible to vary the modulus and/or the degree of vulcanization to suit a particular need. This flexibility in processing conditions is illustrated 6 in Table 8 are based on vulcanizing the ethylenepropylene rubber composition of Table 7 wherein the amine is N,N-diethylamino propyl amine.

EXAMPLE in compositions D via E and F to G by the use of difier- 5 ing quantities of vulcanization agent within wide limits, The vulcanization rates, expressed as modulus percent while s multaneously maitaining the increase in the vulin Table 9 are based on Vulcanizing the ethylenepropyl carliz lzlagltzignrlgiz, ($1 ai g gsr i tortrgztiglmgfo 5132: 2 the bas (331161 lrilibberzcompositiclm ct Table 7 wherein the amine is -a ox -ox ro amine. mixture, 1.e., of the components of the rubber mixture y y yp py not necessary for the vulcanization pro-per, can also be EXAMPLE 6 employed to vary the properties of the vulcanized product Th 1 d 1 correspondingly, again with the high vulcanization rates e camzatlon rates exp as modu us percent being maintained. Such effects are exemplified in the m Table 10 are on vulcamzmg the ethylenepmaylfollowing example ene rubber composition of Table 7 wherein the ammo EXAMPLE 3 is [di-(Z-oxypropyl]-ethanolamine.

The decrease in modulus accompanying the use of the EXAMPLE 7 described method :for increasin the vulcanization velocity is often undesirable. Howevir this concomitant tend- The vulcamzatwn rates expre.ss.ed as modulus Percent ency toward a reduced modulus can be completely or m Tablin are 5 on vulcamzmg the f p fl' partially reversed by varying the composition of the basic Saga fg gigg of Table 7 wherem the amme rubber mixture, the quantity of vulcanization agents be- The g z exam; 168 dead Show that this invem ing kept constant. In the example, a comparatively higher g p y modulus is obtained by omitting the plasticizer compoum} 18 rqad Wlth respect to 9 of ammes capable Dent from the basic rubber mixture 5 of increasing the rate of vulcanization.

Table 5 shows the various compositions used to illus- The precedmg. Q 165 can P repeated i slmllar trate this effect- H is a composition which is conventionsuqcess by substituting the i z speclfi?al.ly deally used: I is a composition according to the method f i reactants operatmg CPHdmOHS of thls mven' of the invention: and K is a composition as in I, but or i 2 piec-edmg g h without the plasticizermm t e oregoing escription, one sk e in t e art Table 6 Shows that the vulcanization velocity as can easily ascertain the essential characteristics of this inpressed by the modulus percentage, increased substantialand wl'tllgout f from l 5pm} scope ly equally in I and K as compared to H but the absolute then-3o a ma 6 various 0 apges an modlficatlqlis of value of the modulus is much higher (L in the case the invention to adapt it to various usages and conditions. of K than in J (-50) Consequently, such changes and modifications are proper- The invention is described in Examples 1 to 3 in coneqpltably and Intended. to wlthm the full range junction with the use of cyclohexylethyl amine. The folof equwalence of the followm'g clams lowing examples show that the same or similar effects TABLE 1-RECIPES can also be achieved with other amines embraced by the 40 A B above generic structural formula. In all of the following Ethylemwlefin rubberunsamated" 100 100 examples, an unsaturated ethylene propylene rubber Stearic acid..... 1 1 mol percent propylene) is used which contains digk gh abms n m 5 5 cyclopentadiene as the unsaturated component in a quan- H 0 Na hthenic plasticizing oil 10 10 tity of about 5% by weight and has a plasticity of 45 Tegamethylthiumm disulfideu 1.5 2.0 ML-4=about 5. Mereaptobenzothiazole 0. 75 EXAMPLE 4 gyclohexyl ethylamme- 8 The vulcanization rates, expressed as modulus percent,

TABLE 2 Mooney Tear viscosity Vulcanizresist- Unsaturated ethylene- Defoof mixing period Tensile Elonga- Modulus ance Elaspropylene rubber ML4= plastieture in minutes strength tion (300%) (kg. 5110- Hardness ticity Mixture ca. 45 ity 2 ML-4 at 160 C. (kg/0111. (percent) (kg/cm!) solute) shore) (22 C.)

I(A) Wt.-perceut DCP} 08. 2.5-.. 1, 750 24 70 15 124 715 41 14 60 45 50 192 605 70 17 45 213 520 94 12 45 120 217 495 104 11 66 47 11(3) Wt.-percent DCP, ea. 2.5.. 1, 750/28 70 15 101 675 36 12 59 43 30 139 590 54 15 60 43 60 136 570 52 16 60 45 121 540 50 1s 60 45 mm) Wt.-percent DCP, ca. 5. 1, 400/20 62 15 198 635 72 16 65 43 50 208 475 115 12 69 45 50 199 400 10 70 45 120 200 395 141 10 70 45 IV(B) Wt.-percent DCP, ea. 5 1,400/22 61 15 635 58 17 61 43 30 183 570 69 15 63 4a 60 174 550 72 i5 64 43 120 152 520 74 14 64 43 V(A) Wt.percent DOP, ca. 9.- 1, 550/23 59 15 212 490 105 13 65 43 30 192 350 156 10 70 45 60 202 335 175 9 70 45 120 198 305 184 9 70 45 VI(B) Wt.-percent DOP, ca. 9 1, 450/27 53 15 205 555 so 15 64 42 30 201 490 97 14 64 43 60 197 475 104 13 65 45 120 450 107 13 65 43 i Dicyclopentadiene. Magnitude of modulus of the vulcanization stage of 30 minutes, expressed in percent of the maximum modulus at. a 300% elongation: I, 67.5; II, 100; III, 80; IV, 93.5; V, 85; VI, 90.5.

3 According to DIN 53 614.

TABLE 3.RECIPE TABLE 7.RECIPE C D E F G L Ethylene-propylene rubber, Ethylene-propylene rubber unsaturation corresponding to unsaturatlon corresponding mixture III or IV 01 Table 2, ML-4=about 45 100 to mixture III or IV of Table 5 Stearic acid 1 2, ML-4=about 45 100 100 100 100 100 Zn 5 Stearic acid 1 1 1 1 1 HAF carbon blaok 50 Zn 5 5 5 5 5 Naphthenlc plasticizer oil 10 HAF carbon blac 50 50 50 50 50 Tetramethyl thiuram disulfide. 2. Naphthenic plasticizer or 10 10 10 10 10 Mercaptobenzothiazole Tetramethylthiuram disulfide- 1. 2 2 2 2 Mercaptobenzothiazole 0. 75 R1 1. 0

0. 5 1 1. 5 1. 5 0. 5 1 1. 5 2.0 N R2 Rs Sulfur 1. 0

TABLE 4 Vulcanizing Tear reperiod in Tensile Elonga- Modulus sistance Elasticity Modulus minutes at strength tion (300 Hardness (22 0.) percent- Mixture 160 C (kg/cm?) (percent) (kg/cm?) absolute) Shore) (percent) ages 1 1 Magnitude of modulus of the vulcanization stage of 30 minutes, expressed in percent of the maximum modulus at a 300% elongation.

TABLE 5.-RECIPES 45 H J K Ethylene-propylene rubber, unsaturation corresponding to mixture I or II of Table 2, ML-

1 1 1 5O 5 5 5 50 50 10 10 Tetramethyl thiuram disulfid 1. 5 2 2 Mercaptobeuzothlazole 0. 75 Cyclohexyl ethylamine 1 1 Sulfur 1. 5 1 1 TABLE 6 Vulcan- Tear izing resistperiod in- Tensile Elonga- Modulus ance Elasticity Modulus minutes strength tion (300%) (kg. ab- Hardness (22 0.) percent- Mixure at 160 C. (kg/cm?) (percent) (kgJcmfl) solute) Shore) (percent) ages 1 Magnitude of modulus of the vulcanization stage of 30 minutes, expressed in percent of the maximum modulus at a 800% elongation.

TABLE 8 Vulcaniz- Tear relng period Tensile Elonga- Modulus sistance Elasticity Modulus in minutes strength tion (300%) (kg. ab- Hardness (22 0.) percent- Mixture withat 160 C. (kg/cm!) (percent) (kg/em!) solute) Shore) (percent ages 1 15 127 645 48 14 61 41 N,N-diethylaminopropylamine 9a See footnote at end of Table 11.

TABLE 9 Vulcaniz- Tear relng period Tensile Elonga- Modulus sistance Elasticity Modulus in minutes strength tion (300%) (kg. ab- Hardness (22 C.) percent- Mixture withat 160 (kg. /cm.*) (percent) (kg/cm?) solute) Shore) (percent) ages l 3-allyloxy-2-oxypropylamine 89 See footnote at end of Table 11.

TABLE Vulcaniz- Tear reing period Tensile Elonga- Modulus sistance Elasticity Modulus in minutes strength tion (300%) (kg. ab- Hardness (22 0.) percent- Mixture withat 160 C. (kg/cm!) (percent) (kg. Icmfi) solute) Shore) (percent) ages 1 208 605 80 14 65 42 [Di-(2-oxypropy1] ethanolamine. g3 g2 i 2; g 92 See footnote at end of Table 11.

TABLE 11 Vulcaniz- Tear reing period Tensile Elonga- Modulus sistance Elasticity Modulus in minutes strength tion (300%) (kg. ab- Hardness (22 0.) percent- Mixture withat 160 C. (kgJcmfl) (percent) (kg/cm?) solute) Shore) (percent) ages 1 15 12).; $5 12 61 41 Di-3-am1n0pr0py1ether b 555 i2 92 120 180 E 83 12 65 42 1 Magnitude of modulus of the vulcanization stage of minutes, expressed in percent of the maximum modulus at a 300% elongation.

What is claimed is:

1. In a process which comprises the vulcanization of an unsaturated rubbery terpolymer of ethylene, an amonoolefin of 3-8 carbon atoms, and based on the Weight of the terpolymer 0.1-20% of a polyunsaturated hydrocarbon of 4-30 carbon atoms and 2-5 double bonds, the improvement comprising employing as vulcanizing ingredients, based on the weight of the copolymer, 0.25-5.0% of an accelerator selected from the group consisting of thiuram accelerators, dithiocarbamate accelerators, and mixtures thereof; 0.25-3.5% sulfur, and (MS-5.0% of an amine selected from the group consisting of cyclohexylamine and an amine of the formula N-Ra wherein R is an alkyl, hydroxyalkyl, alkoxyalkyl or alkenyloxyalkyl residue;

R is H, or a cycloalkyl residue; and

R is H, or an alkyl, hydroxyalkyl, alkoxyalkyl, or

alkenyloxyalkyl residue.

2. A process as defined in claim 1 wherein the copolymer is comprised of 10 to 90 mol percent ethylene, 10 to 80 mol percent of an u-mono-olefin of 3-8 carbon atoms, and 0.1 to 20 percent by weight, based on the weight of the copolymer, of a polyunsaturated hydrocarbon of 4 to 30 carbon atoms and 2 to 5 double bonds.

3. A process as defined by claim 2 wherein said accelerator is tetramethyl thiuram disulfide, tetramethyl thiuram monosulfide, zinc-N-diethyl dithiocarbamate, zinc-N-dibutyl dithiocarbamate, N-cyclohexyl-ethyl-ammonium N cyclohexylethyl-dithiocarbamate, zinc-N-dimethyl dithiocarbamate, zinc-N-ethylphenyldithiocarbamate, zinc-N-pentamethylene dithiocarbamate, dimethyldiphenylthiuramdisulfide, or dipentamethylenethiuramtetrasulfide.

4. A process as defined by claim 2 wherein said amine is cyclohexyl amine, aminopropyl alcohol, l-aminopropan0l-2, n-butyl amine, stearyl amine, lauryl amine, 3-lauryloxy propyl amine, 3-allyloxy-2-oxypropyl amine- 1, [di-(2-oxypropyl)]-ethanolamine, N-(n-butyl)-diethanolamine, cyclohexylethylamine, 3-butoxypropylamine, and (2,2'-dioxy-3,3'-diallyloxy)-dipropylamine.

5. A process as defined by claim 3 wherein said amine is cyclohexyl amine, aminopropyl alcohol, l-aminopropanol-2, n-butyl amine, stearyl amine, lauryl amine, 3- lauryloxy propyl amine, 3-allyloxy-2-oxypropyl amine-1, [di-(Z-oxypropyl) ]-ethanolamine, N-(n-butyl) -diethanolamine, cyclohexylethylamine, 3-butoxypropylamine, and (2,2'-dioxy-3,3-diallyloxy)-dipropylamine.

6. A process as defined by claim 5 wherein said 0:- mono-olefin is propylene, and said polyunsaturated hydrocarbon is dicyclopentadiene, hexadiene-1,4, decatriene- 1,4,9, cyclooctadiene-1,5, norbornene or its alkenyl derivatives.

7. A process as defined in claim 6 wherein the content of accelerator is 1-2%, sulfur is 0.75-1.5%, and amine is 1-2%.

8. A rubber composition composed of an unsaturated rubbery terpolymer of ethylene, an a-mono-olefin of 3-8 carbon atoms and based on the weight of the terpolymer 0.1-20% of a polyunsaturated hydrocarbon of 4-30 carbon atoms and 2-5 double bonds and based on the weight of the copolymer, 0.25-5.0% of an acceleratorselected from the group consisting of thiuram accelerators, dithiocarbamate accelerators, and mixtures thereof, 0.25- 3.5% sulfur, and 0.15-5.0% of an amine selected from the group consisting of cyclohexylamine and an amine of the formula wherein R is an alkyl, hydroxyalkyl, alkoxyalkyl or alkenyloxyalkyl residue;

R is H, or a cycloalkyl residue; and

R is H, or an alkyl, hydroxyalkyl, alkoxyalkyl or al kenyloxyalkyl residue.

9. A rubber as defined by claim 8 wherein the copolymer is comprised of 10 to 90 mol percent ethylene, 10 to 80 percent mol of an a-mono-olefin of 3-8 carbon atoms, and 0.1 to 20 percent by weight, based on the weight of the copolymer, of a polyunsaturated hydrocarbon of 4 to 30 carbon atoms and 2 to 5 double bonds.

10. A rubber as defined by claim 9 wherein said accelerator is tetramethyl thiuram disulfide, tetramethyl thiuram monosulfide, zinc-N-diethyl dithiocarbamate, zinc-N-dibutyl dithiocarbamate, N-cyclohexyl-ethyl-ammonium N cyclohexylethyl-dithiocarbamate, zinc-N-dimethyl dithiocarbamate, zinc-N-ethylphenyldithiocarbamate, zinc-N-pentamethylene dithiocarbamate, dimethyldiphenylthiuramdisulfide, or dipentamethylenethiuramtetrasulfide.

11. A rubber as defined by claim 9, wherein said amine is cyclohexyl amine, aminopropyl alcohol, l-aminopropanel-3, n-butyl amine, stearyl amine, lauryl amine, 3- lauryloxy propyl amine, 3-allyloxy-2-oxypropyl amine-1, [di- (2-oxypropyl] -ethanolamine, N- (n-butyl) -diethanolamine, cyclohexylethylamine, 3-butoxypropylamine, and 2,2'-dioxy-3 ,3 '-diallyloxy) -dipropylamine.

12. A rubber as defined by claim 10 wherein said amine is cyclohexyl amine, aminopropyl alcohol, l-aminopropano1-2, n-butyl amine, stearyl amine, lauryl amine, 3- lauryloxy propyl amine, 3-al1yloxy-2-oxypropyl amine-1, [di-(2-oxypropyl) -ethano1amine, N- (n-butyl) -diethanolamine, cyclohexylethylamine, 3-butoxypropylamine, and (2,2-dioxy-3,3'-diallyloxy)-dipropylamine.

13. A rubber as defined by claim 12 wherein said ot mono-olefin is propylene, and said poly-unsaturated hy drocarbon is dicyclopentadiene, hexadiene-1,4, decatriene- 1,4,9, cyclooctadiene-1,5, norbornene or its alkenyl derivatives.

14. A rubber as defined by claim 13 wherein the content of accelerator is 12%, sulfur is 0.751.5%, and amine is 12%.

15. A process as defined by claim 1 wherein said amine is cyclohexylethylamine.

16. A process as defined by claim 2 wherein said amine is cyclohexylethylamine.

17. A process as defined by claim 3 wherein said amine is cyclohexylethylamine.

18. A rubber as defined by claim 8 wherein said amine is cyclohexylethylamine.

19. A rubber as defined by claim 9 wherein said amine is cyclohexylethylamine.

20. A rubber as defined by claim 10 wherein said amine is cyclohexylethylamine.

21. A rubber as defined by claim 14 wherein said amine is cyclohexylethylamine.

References Cited UNITED STATES PATENTS 3,211,709 10/ 1965 Adamek et al 26080.78 3,345,325 10/ 1967 Martin 260-79.5 B 1,783,216 12/1930 Bogemann et al 260-798 2,878,232 3/ 1959 Schweitzer, Jr. 260-45.9 2,939,867 6/ 1960 Ambelang 260-79.5 3,260,708 7/1966 Natta et al 260-79.5 3,268,493 8/1966 Reynolds et al 260-79.5 2,223,446 12/ 1940 Harman 260-787 2,335,059 11/1943 Harman 260-787 2,457,335 12/ 1948 Williams et al. 260-27 JAMES A. SEIDLECK, Primary Examiner US. Cl. X.R.

UNITED STATES OFFICE CERTIFICATE OF CORRECTION Patent No. 3,654,243 Dated April 4, 1972 Inventor(s) HARALD BLUEMEL It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 16: after "percent" add -of--.

Column 8, line 22, in Table 4 under Modulus pe'roentages;

change "65" to ss--.

Signed and sealed this 21st day oi Hay 1971+.

(SEAL) Attest: I U o EDB-JARD l-LFLETGl-fiilfi, JR. 0. MARSHALL DANN Attes'ting Officer l 1 Commissioner of Patents 

